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        <h2>
          <span class="refentrytitle">logcurve</span>
        </h2>
        <p>logcurve — 
      This opcode implements a formula for generating a normalised logarithmic curve in range 0 - 1. It is based on the Max / MSP work of Eric Singer (c) 1994.
    </p>
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      <div class="refsect1">
        <a id="idp119811040"></a>
        <h2>Description</h2>
        <p>
      Generates a logarithmic curve in range 0 to 1 of arbitrary steepness.
      Steepness index equal to or lower than 1.0 will result in Not-a-Number
      errors and cause unstable behavior.
    </p>
        <p>
      The formula used to calculate the curve is:
</p>
        <pre class="programlisting">log(x * (y-1)+1) / (log(y)</pre>
        <p>
      where x is equal to <span class="emphasis"><em>kindex</em></span> and y is equal to <span class="emphasis"><em>ksteepness</em></span>.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp119814784"></a>
        <h2>Syntax</h2>
        <pre class="synopsis">kout <span class="command"><strong>logcurve</strong></span> kindex, ksteepness</pre>
      </div>
      <div class="refsect1">
        <a id="idp119817024"></a>
        <h2>Performance</h2>
        <p>
      <span class="emphasis"><em>kindex</em></span> -- Index value. Expected range 0 to 1.
    </p>
        <p>
      <span class="emphasis"><em>ksteepness</em></span> -- Steepness of the generated curve. Values
      closer to 1.0 result in a straighter line while larger values steepen the
      curve.
    </p>
        <p>
      <span class="emphasis"><em>kout</em></span> -- Scaled output.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp119820704"></a>
        <h2>Examples</h2>
        <p>
      Here is an example of the logcurve opcode. It uses the file <a class="ulink" href="examples/logcurve.csd" target="_top"><em class="citetitle">logcurve.csd</em></a>.

      </p>
        <div class="example">
          <a id="idp119822480"></a>
          <p class="title">
            <strong>Example 433. Example of the logcurve opcode.</strong>
          </p>
          <div class="example-contents">
            <p>See the sections <a class="link" href="UsingRealTime.html" title="Real-Time Audio"><em class="citetitle">Real-time Audio</em></a> and <a class="link" href="CommandFlags.html" title="Csound command line"><em class="citetitle">Command Line Flags</em></a> for more information on using command line flags.</p>
            <pre class="programlisting">
<span class="csdtag">&lt;CsoundSynthesizer&gt;</span>
<span class="csdtag">&lt;CsOptions&gt;</span>
<span class="comment">; Select audio/midi flags here according to platform</span>
<span class="comment">; Audio out   Audio in    Silent</span>
-odac           -iadc     -d    <span class="comment">;;;realtime output</span>
<span class="csdtag">&lt;/CsOptions&gt;</span>
<span class="csdtag">&lt;CsInstruments&gt;</span>

<span class="ohdr">sr</span>	<span class="op">=</span>	48000
<span class="ohdr">ksmps</span>	<span class="op">=</span>	100
<span class="ohdr">nchnls</span>	<span class="op">=</span>	2

		<span class="oblock">instr</span>	1	<span class="comment">; logcurve test</span>

kmod	<span class="opc">phasor</span>	1<span class="op">/</span>p3

kout	<span class="opc">logcurve</span> kmod, p4

	<span class="opc">printks</span> "kmod <span class="op">=</span> <span class="op">%</span>f  kout <span class="op">=</span> <span class="op">%</span>f\\n", 0.1, kmod, kout

		<span class="oblock">endin</span>

<span class="csdtag">&lt;/CsInstruments&gt;</span>
<span class="csdtag">&lt;CsScore&gt;</span>

<span class="stamnt">i</span>1	0	10 2
<span class="stamnt">i</span>1	10	10 30
<span class="stamnt">i</span>1	20	10 0.5

<span class="stamnt">e</span>
<span class="csdtag">&lt;/CsScore&gt;</span>
<span class="csdtag">&lt;/CsoundSynthesizer&gt;</span>
</pre>
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        <p><br class="example-break" />
    </p>
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      <div class="refsect1">
        <a id="idp119826800"></a>
        <h2>See Also</h2>
        <p>
      <a class="link" href="scale.html" title="scale"><em class="citetitle">scale</em></a>,
      <a class="link" href="gainslider.html" title="gainslider"><em class="citetitle">gainslider</em></a>,
      <a class="link" href="expcurve.html" title="expcurve"><em class="citetitle">expcurve</em></a>
    </p>
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      <div class="refsect1">
        <a id="idp119830832"></a>
        <h2>Credits</h2>
        <p>
      </p>
        <table border="0" summary="Simple list" class="simplelist">
          <tr>
            <td>Author: David Akbari</td>
          </tr>
          <tr>
            <td>October</td>
          </tr>
          <tr>
            <td>2006</td>
          </tr>
        </table>
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